Nearly half the species on the planet are failing to cope with global warming the world has already experienced, according to an alarming new study that suggests the sixth mass extinction of animal life in the Earth's history could take place in as little as 50 years.
A leading evolutionary biologist, Professor John Wiens, found that 47 per cent of nearly 1,000 species had suffered local extinctions linked to climate change with populations absent from areas where they had been found before.
Professor Wiens, who is editor of the Quarterly Review of Biology and a winner of the American Society of Naturalists' Presidential Award, said the implications for the future were serious because his review showed plants and animals were struggling to deal with the relatively small amount of global warming experienced to date.
So far the world has warmed by about 1C above pre-industrial levels, but it is expected to hit between 2.6 and 4.8C by 2100 if nothing is done to reduce greenhouse gases.
Another problem facing life on Earth is the election of climate science denier Donald Trump as US president.
Professor Wiens, of Arizona University, described this as a "global disaster" and, when asked what he would say to the President-elect if he met him, he joked grimly: "Kill yourself immediately."
In his study, published in the journal PLOS Biology, the scientist examined academic papers about 976 different species from all over the world that had been studied at least twice, once about 50 years ago and again within the last 10 years.
"In almost half the species looked at, there have been local extinctions already," he said.
"This is stuff that's already happened with just a small change to the climate. We're looking at a two to five-fold increase [in warming over the next century].
"What it shows is species cannot change fast enough to keep up with a small change in climate. That's the big implication - even a small change in temperature and they cannot handle it."
The study looked at 716 different kinds of animals and 260 plants from Asia, Europe, North and South America, and elsewhere.
Local extinctions were found to have occurred among 47.1 per cent of species at the "warm edge" of their traditional range, as it became too hot for them. There were few areas of the planet that were unaffected.
"Overall, the frequency of local extinctions was similar across most climatic zones, habitats, gradients and clade," the PLOS Biology paper said.
However Professor Wiens found climate-related local extinctions were "substantially higher" among freshwater species at 74 per cent of the 31 studied.
The current rate of global extinction of animals and plants is believed to be faster than some of the five great extinction events in the Earth's history, but so far the total number lost does not compare to the species lost when the dinosaurs were wiped out about 65 million years ago.
However one reason geologists are considering declaring a new epoch in the planet's history is the rapid loss of flora and fauna that will have a noticeable effect on the fossil record.
Professor Wiens said: "It's true that in terms of global extinction of entire species that have already happened, I think we're not there [at the sixth mass extinction] yet.
"But I think unfortunately we are on track for that to happen.
"That's sort of the good news - it hasn't happened yet. But if we don't do anything it seems like that's going to happen in the next 50 to 100 years."
There were already "two bad signs" that Mr Trump's election would make things worse, Professor Wiens said.
"One would be this person he's assigned to head the EPA [renowned climate science denier Scott Pruitt] and the other thing is pulling out of the Paris accord [on climate change]," he said.
"The EPA in this country, they are the ones supposed to be protecting the environment."
In what was perhaps a sign of the desperation felt by environmental scientists in the US and elsewhere, he jokingly suggested the UK should invade the US or the US and Canada should swap leaders with Justin Trudeau taking over in the White House.
Asked what he would really say to Mr Trump if they met, Professor Wiens said: "I guess I would tell him 'what would you think if there was a country on the other side of the world that was releasing gas that was going to cause extinctions in our country, to hurt our crops and make people starve'.
"He would say, 'tell me where it is and we'll bomb them tomorrow'. Then I'd say, 'this is what we're doing to other countries because we are the big polluters.'
"People are already having serious problems with food security. People are going to die and it's going to be the fault of our country and other big polluters.
"There is no question he would militarily intervene against a country that was doing to us what we are doing to other countries."
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